Predatory tank questions

I’m planning ahead for when I move out and want to set up a heavily planted tank with some kind of exotic predator as the main fish. I’m open to both freshwater and saltwater, so what species would you look into and what tank size would you actually aim for (not just the bare minimum)? What tank mates work safely with your predators, and what did you learn the hard way about aggression, messiness, or plants getting wrecked? Pics of your predator tanks or any channels/resources to check out would be awesome too.